title: The E1015K variant in the synprint region of the CaV2.1 channel alters channel function and is associated with different migraine phenotypes.
abstract: Mutations in the CACNA1A gene, which encodes the pore-forming α1A subunit of the CaV2.1 voltage-gated calcium channel, cause a number of human neurologic diseases including familial hemiplegic migraine. We have analyzed the functional impact of the E1015K amino acid substitution located in the "synprint" domain of the α1A subunit. This variant was identified in two families with hemiplegic migraine and in one patient with migraine with aura. The wild type (WT) and the E1015K forms of the GFP-tagged α1A subunit were expressed in cultured hippocampal neurons and HEK cells to understand the role of the variant in the transport activity and physiology of CaV2.1. The E1015K variant does not alter CaV2.1 protein expression, and its transport to the cell surface and synaptic terminals is similar to that observed for WT channels. Electrophysiological data demonstrated that E1015K channels have increased current density and significantly altered inactivation properties compared with WT. Furthermore, the SNARE proteins syntaxin 1A and SNAP-25 were unable to modulate voltage-dependent inactivation of E1015K channels. Overall, our findings describe a genetic variant in the synprint site of the CaV2.1 channel which is characterized by a gain-of-function and associated with both hemiplegic migraine and migraine with aura in patients.
authors.affiliation: Department of Physiology, University of Otago, 9054 Dunedin, New Zealand. Electronic address: steven.condliffe@otago.ac.nz.
authors.forename: Steven B
authors.initials: SB
authors.lastname: Condliffe
authors.affiliation: Consiglio Nazionale delle Ricerche Institute of Neuroscience, Department of Medical Biotechnologies and Translational Medicine (BIOMETRA), University of Milan, 20129 Milan, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Fratangeli
authors.affiliation: Department of Physiology, University of Otago, 9054 Dunedin, New Zealand.
authors.forename: Nehan R
authors.initials: NR
authors.lastname: Munasinghe
authors.affiliation: Consiglio Nazionale delle Ricerche Institute of Neuroscience, Department of Medical Biotechnologies and Translational Medicine (BIOMETRA), University of Milan, 20129 Milan, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Saba
authors.affiliation: Consiglio Nazionale delle Ricerche Institute of Neuroscience, Department of Medical Biotechnologies and Translational Medicine (BIOMETRA), University of Milan, 20129 Milan, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Passafaro
authors.affiliation: Center of Translational Genomics and Bioinformatics and Laboraf, San Raffaele Hospital, 20132 Milan, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Montrasio
authors.affiliation: Center of Translational Genomics and Bioinformatics and Laboraf, San Raffaele Hospital, 20132 Milan, Italy; Vita-Salute University, Clinical Pathology, 20132 Milan, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Ferrari
authors.affiliation: Consiglio Nazionale delle Ricerche Institute of Neuroscience, Department of Medical Biotechnologies and Translational Medicine (BIOMETRA), University of Milan, 20129 Milan, Italy. Electronic address: p.rosa@in.cnr.it.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Rosa
authors.affiliation: Center of Translational Genomics and Bioinformatics and Laboraf, San Raffaele Hospital, 20132 Milan, Italy. Electronic address: carrera.paola@hsr.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Carrera
mesh_terms: D000293:Adolescent; D000328:Adult; D019943:Amino Acid Substitution; D000818:Animals; D020864:Calcium Channels, N-Type / Q000235:genetics / Q000378:metabolism; D002648:Child; D005260:Female; D057809:HEK293 Cells; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology; D006801:Humans; D017136:Ion Transport / Q000235:genetics; D008297:Male; D008875:Middle Aged; D020325:Migraine with Aura / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020125:Mutation, Missense; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D017729:Presynaptic Terminals / Q000378:metabolism / Q000473:pathology; D011817:Rabbits; D051381:Rats; D050825:Synaptosomal-Associated Protein 25 / Q000235:genetics / Q000378:metabolism; D050827:Syntaxin 1 / Q000235:genetics / Q000378:metabolism
chemical_list: D020864:Calcium Channels, N-Type; D009419:Nerve Tissue Proteins; D050825:Synaptosomal-Associated Protein 25; D050827:Syntaxin 1; C494208:SNAP25 protein, human; C494212:STX1A protein, human; C494210:Snap25 protein, rat; C494213:Stx1a protein, rat
keywords: Calcium Channels; Genetics; Migraine; Neurological Diseases; Protein-Protein Interactions; SNARE Proteins